Zimbabwe's army has threatened to evict the country's remaining white farmers if a single vote is cast for Morgan Tsvangirai, the opposition leader, in polling stations on their land.

The final round of the presidential election will take place on June 27 and Robert Mugabe's regime is trying to guarantee his victory with a violent crackdown on opponents.

At least 42 people have been murdered and thousands assaulted since Mr Tsvangirai defeated Mr Mugabe in the first round on March 29, although he fell short of the 50 per cent threshold needed to avoid a run-off.

Five landowners from two different districts were called to a meeting last week by a lieutenant colonel in the army, whose name is known to The Daily Telegraph. He was accompanied by three senior officials from Mr Mugabe's Zanu PF party.

During the 90-minute meeting the colonel told the farmers: "I do not accept failure, and Mugabe has to win. If he doesn't win we will go back to war. Tsvangirai and the MDC [Movement for Democratic Change] will never rule Zimbabwe. If there is one MDC vote on your farm, there will be war."

The colonel, who is in his early 40s and fought in Zimbabwe's military interventions in Mozambique and the Democratic Republic of Congo, told the farmers to ensure that Mr Tsvangirai received no votes on their land.

A farmer who attended the meeting, and who spoke on condition of anonymity, described how Mr Mugabe's re-election campaign was operating in his district.

He said "command centres" had been established in old homesteads once occupied by white farmers or in deserted schools.